Implementation and Proof-checking of Mechanistic-empirical Pavement Design for Indian Highways Using AASHTOWARE Pavement ME Design Software

Abstract

In the current practice of flexible pavement design as per Indian Roads Congress (IRC), the influence of cyclic change in pavement temperature, traffic speed and aging on the material behaviour has not been considered. However, these factors influences the behavior of bituminous mixture and hence the pavement thickness. In this investigation, the influence of temperature, vehicle speed and aging on the dynamic modulus of the bituminous mixture was considered and an IRC pavement cross section was analyzed using AASHTOWARE pavement ME design software. The traffic data required for the design was collected from an existing National Highway and weather data used corresponds to Chennai city. For material characterization, two types of bituminous mixture sample were fabricated in the laboratory satisfying the Bituminous Concrete grade-2 (BC-2) and Dense Bituminous Macadam grade (DBM) specification of the Ministry of Road Transport and Highways, India. The dynamic modulus of these samples were measured at frequencies ranging from 0.01 to 25Hz at temperatures ranging from 5 to 55°C and the mater curve was constructed and used in the pavement design. It was found that most of the cross-sections failed to satisfy the design requirements when subjected to rigorous analysis, design and proof- checking. For a target life of 8 years, the required thickness of the bituminous layer was worked out and the thickness was found to be considerably high when compared to the existing thickness as proposed in the IRC guidelines.